Trait ObjectSetMethods

Source

pub trait ObjectSetMethods: Copy + Sized {
    type Each: Sized;
    type Field: Sized;

    // Required method
    fn resolve_option(
        self,
        found: Option<Self::Each>,
    ) -> Result<Self::Field, EP>;

    // Provided methods
    fn check_label(self, label: &str) -> Result<(), EP>
       where Self::Each: ItemObjectParseable { ... }
    fn check_object_parseable(self)
       where Self::Each: ItemObjectParseable { ... }
}

Available on crate feature parse2 only.

Expand description

Method for handling some multiplicity of Objects

For use by macros.

See the module-level docs, and Field type in ItemValueParseable.

§Example

The code in the (derive) macro output is roughly like this:

use tor_netdoc::parse2::multiplicity::{MultiplicitySelector, ObjectSetMethods as _};
use tor_netdoc::parse2::{ItemStream, ParseInput};
let doc = "intro-item\n-----BEGIN OBJECT-----\naGVsbG8=\n-----END OBJECT-----\n";
let input = ParseInput::new(doc, "<literal>");
let mut items = ItemStream::new(&input).unwrap();
let mut item = items.next().unwrap().unwrap();

let selector = MultiplicitySelector::<Option<String>>::default();
let obj = item.object().map(|obj| {
    let data = obj.decode_data().unwrap();
    String::from_utf8(data)
}).transpose().unwrap();
let obj = selector.resolve_option(obj).unwrap();
assert_eq!(obj, Some("hello".to_owned()));